The Hajj pilgrimage draws millions of Muslims from around the world every year to Mecca, the birthplace of the Prophet Muhammad, Islam's holiest place. Saudi Arabia expects to host perhaps three million people in a ritual journey that every able-bodied Muslim who can afford it must make at least once in their lifetime. It is the largest annual gathering of humanity anywhere. Timed to the Muslim lunar calendar, the Hajj is followed by the celebrations of the three-day festival of Eid al-Adha, or the Feast of Sacrifice, which symbolizes Abraham's willingness to sacrifice his son. Collected here are photographs of the Hajj in Mecca, Saudi Arabia, as well as images of preparations for the Hajj and Eid al-Adha in many other parts of the Muslim world. -- Lane Turner (42 photos total)

A Muslim pilgrim prays as visits the Hiraa cave at the top of Noor Mountain on the outskirts of Mecca, Saudi Arabia on November 2, 2011. According to tradition, Islam's Prophet Mohammed received his first message to preach Islam while he was praying in the cave. (Hassan Ammar/AP)

The Mecca CLock Tower dominates the city as Muslim pilgrims walking around the Kaaba in the Grand Mosque of the holy city of Mecca during the annual Hajj pilgrimage rituals on November 7, 2011. (Fayez Nureldine/AFP/Getty Images) #

Muslim pilgrims wait in line as they arrive at Jeddah airport on October 30, 2011 before going to the Saudi holy city of Mecca, where they will take part in the annual Hajj or pilgrimage. (Fayez Nureldine/AFP/Getty Images) #

Muslim pilgrims cast stones at a pillar, symbolizing the stoning of Satan, in a ritual called "Jamarat," the last rite of the annual hajj, in Mina near the Saudi holy city of Mecca, Saudi Arabia on November 6, 2011. (Hassan Ammar/AP) #

Muslim pilgrims protect their heads from stones thrown by others at a pillar, symbolizing the stoning of Satan, in a ritual called "Jamarat," the last rite of the annual hajj, in Mina near the Saudi holy city of Mecca, Saudi Arabia on November 6, 2011. (Hassan Ammar/AP) #

Thousands of Muslim pilgrims arrive to throw pebbles at pillars during the "Jamarat" ritual, the stoning of Satan, in Mina near the holy city of Mecca, on November 6, 2011. (Fayez Nureldine/AFP/Getty Images) #

Thai Muslim pilgrims offer prayers before they depart for the annual Hajj pilgrimage to Mecca at the Hat Yai International airport in southern Thailand on October 5, 2011. (Muhammad Sabri/AFP/Getty Images) #

Indonesian pilgrims conduct a practice run of a religious ritual before a mock-up of the Kabaa, Islam's holy shrine, at a training center in Jakarta as part of final preparations before departing for the hajj pilgrimage in Mecca on October 28, 2011. For the world's largest Muslim-majority country with more than 200,000 pilgrims each year, the training is crucial in preventing chaos and casualty in the holy land, officials say. (Bay Ismoyo/AFP/Getty Images) #

Yemenis shop at a market in Sanaa on November 3, 2011, in preparation for the Eid al-Adha feast, or Feast of Sacrifice, which marks the end of the annual hajj pilgrimage for Muslims worldwide. (Mohammed Huwais/AFP/Getty Images) #

A Kyrgyz vendor handles a sheep at the outdoor livestock market in Bishkek on the eve of the Muslim Eid al-Adha festival, known locally as Kurban Bairam, on November 5, 2011. (Vyacheslav Oseledko/AFP/Getty Images) #

Palestinian youngsters enjoy a carnival ride in the Palestinian Shatila refugee camp in Beirut on November 6, 2011, as Muslims worldwide celebrate the first day of Eid al-Adha. (Anwar Amro/AFP/Getty Images) #

Palestinians arrive at Damascus Gate leading into the old city of Jerusalem on their way to pray in the Al-Aqsa Mosque compound, Islam's third holiest site, on November 6, 2011, on the first day of the Muslim festival of Eid al-Adha. (Menahem Kahana/AFP/Getty Images) #

Muslim women attend prayer on the slopes of Mount Merapi (in the background) to celebrate the festival of Eid al-Adha in the village of Kalitengah Lor outside city of Yogyakarta, Central Java on November 6, 2011. (Dwi Oblo/Reuters) #

A Muslim man attends a prayer session on Eid al-Adha in Tehran on November 7, 2011. (Editor's note: Reuters and other foreign media are subject to Iranian restrictions on their ability to film or take pictures in Tehran.) (Morteza Nikoubazl/Reuters) #